Method of making level faced matrices



Dec. 28, 1937.

c. E. BOUTWELL Filed Feb. 15, 1936 IEIFQIEEIIEHEIFIIEIII'IEIII in;QEIEIIQILEIE gum EllgllgllgjlllLglLgllJHElEl I ll!lEIIQIEIIQIIQIEIEIIEIEI /7 [25 Z /IB WWW {/727 INVENTOR umrence. E.BouTwe ATTORNEYS:

Patented Dec. 28, 1937 UNITED STATES PATENT OFFICE METHOD OF MAKINGLEVEL FACED MATRICES This invention relates to a method for makingmatrices for printing plates, and has for its object the provision of amethod of the character designated which shall be effective to producein ,5 a minimum of operations a matrix in which all of the details of adesign or setup may be reproduced without further levelling upof theprinting surface. V

A further object of my invention is to provide a leveling device for waxmodels employed in making my improved matrices, which shall be effectiveto insure that all surfaces in relief on the model shall be brought intoproper relation with each other, e

l8 My invention particularly contemplates the developrnent of a hardsurfaced matrix, such as of plaster of Paris, or what is known assynthetic stone, such as is employed for reproducing finer ;gg producefine work, such as fine screen photo etchings,and line work,particularly where there are a plurality of fine lines or 'points, thatthe lines or points in relief on the printing surface must be perfectlyeven with respect to each other in 39 .order that all parts of the platebear with equal pressure upon the paper when the printing is being done.Also, as is well known in this art, the more nearly perfect leveling isaccomplished on a printing plate, the less make ready is re- 35 quiredin preparing the setup for printing.

My invention also contemplates a method whereby hand work, such as artdesigns, and line work, may be employed in the designing of the 7 plate,and all of the lines and figuresthereby x40 produced be brought intoproper prominence ion the plate for printing. h In the art of printing,as now known to me, printing plates, such. as electrotypes or moldedplates, are first made with a suitable matrix to bring the lines orprominent printing surfaces into relief, and after being made arelevelled up by polishing off the higher parts of the printing surface ona level stone, and also by backing the printing shell with lead andpunching the backing with suitable tools to bring the lower surfacesintotheir proper position of relief. My invention particularlycontemplates the avoiding of this work which requires considerable timeand highly skilled labor, and the production of, a matrix carrying allof the fine details to be reproduced in proper relief position.

Briefly, my invention contemplates the making of an intaglio impressionin a preliminary matrix capable of receiving and retaining an 5impression of the minute details of the design to be printed, the makingof a wax model from the intaglio impression, the leveling of the waxmodel by a mounting upon a suitable grid and the application ofpressure, and the casting of a suit- .10

able hard matrix therefrom.

In the accompanying drawing forming a part of this application,

Figs. 1 and 2 are viewsshowing the steps of forming a preliminary matrixin my improved method;

Fig. 3 is a view. showing the step of forming a Wax model from thepreliminary matrix;

Fig. 4 is a view showing the device employed and the method of levelingup of the wax model;

Fig. 5 is a plan View of the device employed in leveling up the waxmodel; and

Fig. 6 is a view showing the step of forming a plaster of Paris orsynthetic stone matrix from the wax model.

Referring to the drawing, I first take a sheet of a material capable ofreceivingand retaining an impression, such as a fiong of paper or heavysheet of blotting paper I0, and apply thereover a coating of cement madeby dissolving rubber in benzol, or any other cement having the property'of separably holding the sheets together. Over the fiong or sheet ID asthus prepared, I place a sheet of relatively heavy metal foil II. Themetal foil used for this purpose is in the neighborhood of 0.004 inch inthickness. The fiong or sheet In and the heavy foil sheet I I serve as afoundation over which is applied another coating oi' cement, and overthis is placed a sheet of relatively thin foil [2, the upper sheet offoil be- 40 ing of the order of 0.0015 inch in thickness. I

The purpose of the cement over the sheet l0 and over the sheet of foil ll is to provide a yieldable substance beneath the sheets of foil toprevent its being cut ortorn by the finer or, sharper points or lines tobe reproduced, .and'to hold the 'may. be made by a printing setup, ormanually by a stylus. Fig. 2 of the drawing shows the I assemblyplacedon the lower platen I 3 of a suitable press with a printing form I4ready to be pressed down into the sheets of foil II and I2 by the upperplaten E6 of the press.

The impression thus made in the foil I2 is now ready for the preparationof a wax model. This step is shown in Fig. 3, in which the sheet In andthe sheets of foil II and I2 are shown resting on a fiat surface I5 andsurrounded by a suitable frame I1, and in this is poured melted wax I8,the wax being of a consistency comparable to that of mixed beeswax andparaffin.

As soon as the wax is cooled and hardened,

The purpose of retaining the thin sheet of foil 7 I2 on the wax model atthis stage in the process is to prevent sticking of the wax in the stepsof the process to follow. The foil employed may be any of the commercialsoft metal foils, such as lead foil, solder foil, tin foil, and copperfoil.

The foil covered wax model I8 is next placed, as shown in Fig. 4, upon agrid shown in section in Fig. 4 and in plan in Fig. 5, the gridcomprising preferably a multiplicity of evenly spaced sharp prominenciesor knife edges I9. The purpose of this grid is to provide a support forthe wax model such that, upon applying pressure to the model it may beforced downwardly with the knife edges sinking into the wax. At the fourcorners of the grid I8 are stops 29, the upper surfaces of which areeven with respect to each other. A smooth rigid plate of glass of othersuitable material is then placed over the foil covered wax model, asshown in Fig. 4, and is pressed down evenly with the hands, orotherwise, toward the grid until the sheet of glass comes in contactwith the stops 2!). The operator can observe through the glass when alllines or figures in the design on the model are in contact with theunder surface of the glass. When this is accomplished, the wax model isperfectly leveled and is ready for the formation of the hard matrix.

It will be seen that in pressing downwardly upon the wax model with thesheet of glass 25, the pressure will be concentrated on the moreprominent surfaces, causing the model opposite such surfaces to sinkmore deeply into the grid I9. The stops 29 should be removable and setsof different lengths provided to accommodate models of differentthicknesses.

If a matrix having absolute fidelity of detail is desired, therelatively thin sheet of foil I2 is next stripped off the wax model;otherwise and ordinarily, it is left in place. A suitable frame 2I isnext placed around the grid I9 and the wax model I8, as shown in Fig. 6,and a suitable cement, such as plaster of Paris, synthetic stone, orother fine cement 25, is poured into the frame over the wax model. Whenthis cement has set, the hard matrix is formed with an intaglioimpression of the original design, ready for the casting or productionof printing plates in' any manner that may be desired, therefrom.

From the foregoing description it will be apparent that my improvedprocess is particularly adapted to the formation of printing plateswhere manual design is involved. In the drawing of designs directly uponthe preliminary matrix shown in Figs. land 2, it is practicallyimpossible to have the lines of equal depth in the foil receiving theimpression, throughout their length, or to have different lines of equaldepth in the foil. Where a design is thus applied to the foil inaccordance with my process, and a wax model made, the lines are allbrought to an equal height on the model by the procedure shown in Fig. 4of the drawing, that is, by placing the model upon the sharp points ofthe grid and pressing downwardly on the model with the smooth sheetof'glass. The method is also obviously of value in leveling up thesurfaces produced by a printing setup, wherein, as is well known, it isextremely difficult to have the various printing surfaces of equalprominence in the setup.

While the finer details of reproduction are accomplished by means of thepreliminary matrix illustrated in Figs. 1 and 2, where reproductions ofprinting setups alone are to be made, the preliminary matrix may be madein any suitable manner other than that described herein, and a wax modelmade therefrom, as described in connection with Fig. 3 of the drawing,and leveled up as described in connection with Fig. 4 of the drawing.

The thin foil I2 employed by me for making the preliminary matrix is sosensitive to impressions that accurate reproductions of fine screenedphoto etchings can be reproduced with greater fidelity than is possiblewith an electroplating I ing or drawing of designs upon the thin foil,

where it is necessary to employ a very sharp pointed stylus, I recommendthe placing of a thin sheet of transparent material, such as a sheet ofregenerated cellulose, between the stylus and the thin foil.

While I have shown my invention in but one form, it will be obvious tothose skilled in the art that it is not so limited, but is susceptibleof various changes and modifications, without departing from the spiritthereof, and I desire, therefore, that only such limitations shall beplaced thereupon as are imposed by the prior art or as are specificallyset forth in the appended claims.

What I claim is:

1. The method of producing matrices for printing plates which comprisesfirst forming a preliminary matrix by superposing a relatively thinmetal foil sheet over a foundation of yieldable material capable ofreceiving and retaining an impression,

forming an impression in the preliminary matrix ing plates whichcomprises first forming a preliminary matrix by superposing a relativelythin metal foil sheet over a foundation of yieldable material capable ofreceiving and retaining an impression, forming an impression in thepreliminary matrix by impressing a design into the metal I foil, forminga wax cameo model from the preliminary matrix, stripping the foundationfrom the wax model leaving thereon a sheet of metal foil, mounting thewax model thus formed upon a grid comprising a multiplicity of sharpprominencies, leveling the cameo surfaces of the model by pressingdownwardly thereon with a smooth level surfaced member, and casting ahard intaglio matrix from the Wax model.

3. The method of making matrices for printing plates which comprisesforming an intaglio impression to be reproduced in relatively thin metalfoil, forming a cameo wax model from the metal foil impression, mountingthe wax model on a grid comprising a multicipility of sharp points,leveling the model by pressing downwardly on the metal foil with asmooth level surfaced instrument,

and casting a hard matrix from the model thus 5 leveled.

* CLARENCE E. BOU'IWELL.

